Glu43 is an essential residue for coordinating the [Fe2S2] cluster of IscR from Acidithiobacillus ferrooxidans.
The iron-sulfur cluster regulator (IscR) was reported to be a repressor of the iscRSUA operon. In vitro transcription reactions revealed that the IscR had a repression effect on the iscR promoter. The IscR contains a [Fe2S2] cluster per each monomer, and three highly conserved cysteines were identified to ligate the [Fe2S2] cluster. It was proposed that a non-cysteine residue might be the fourth ligand for the [Fe2S2] cluster. In this study, using site-directed mutagenesis, Glu43 was found to be the fourth residue that coordinates the [Fe2S2] cluster of IscR.
Zeng
Jia
J
Department of Bioengineering, School of Resources Processing and Bioengineering, Central South University, Changsha, Hunan 410083, PR China. zengjcsu@yahoo.com.cn
Zhang
Xiaojian
X
Wang
Yiping
Y
Ai
Chenbing
C
Liu
Qing
Q
Qiu
Guanzhou
G
D042763:Acidithiobacillus / Q000378:metabolism*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D017124:Conserved Sequence; D004578:Electron Spin Resonance Spectroscopy; D018698:Glutamic Acid / Q000235:genetics / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000235:genetics / Q000378:metabolism*; D008024:Ligands; D008969:Molecular Sequence Data; D009154:Mutation
D001426:Bacterial Proteins; D007506:Iron-Sulfur Proteins; D008024:Ligands; D018698:Glutamic Acid